1. Field of the Invention
The present invention concerns wireless communications, and more specifically, to an uplink transmission method.
2. Related Art
M2M (machine to machine)/IoT (Internet of Things) recently gains attention, as a main issue, in the next-generation communication market for connecting all the ambient things to each other via a network to provide for easy acquisition and delivery of necessary information anytime and anywhere and to resultantly provide for various services. The initial type of M2M primarily focused on sensors and RFID (Radio Frequency Identification) networks targeting local areas. However, more attention is nowadays oriented towards the mobile communication network-based M2M considering mobility of things, a wide service range including islands or mountainous areas or marine areas, easy operation or maintenance of networks, security for high-reliability data transmission, and guarantee of service quality.
The 3GPP, a representative European mobile communication standardization organization, since having studied feasibility on M2M on 2005, started standardization under the title “Machine Type Communications (MTC)” from 2008.
In view of the 3GPP, the term “machine” refers to an entity that does not require direct manipulation or involvement of human beings, and the term “MTC” is defined as a type of data communication including one or more of such type of machines.
As a typical example of the machine, a smart meter or vending machine equipped with a mobile communication module is referenced. As the smartphone appears that may automatically gain access to a network to conduct communication even without the user's manipulation or involvement depending on the user's position or condition, the portable terminals with the MTC function are also taken into account as a type of the machine. Further, a gateway-type MTC device connected with IEEE 802.15 WPAN (Wireless Personal Area Network)-based microsensors or RFIDs are also being considered as an MTC device.
To encompass a great number of MTC devices communicating a small amount of data, the mobile communication network requires an identifier and address system different from the conventional ones and may need a new mechanism considering communication schemes and costs.